KR20240068657A - Power storage device separator binder aqueous solution, power storage device separator slurry, power storage device separator, power storage device separator/electrode laminate, and power storage device. - Google Patents

Abstract

An aqueous solution of an electrical storage device separator binder, wherein the aqueous solution of an electrical storage device separator binder contains a water-soluble polymer (1) or a water-soluble polymer (2) and a hydrazide, wherein the water-soluble polymer (1) is N, N-di. Containing 20 mol% to 80 mol% of alkyl (meth)acrylamide units and 10 mol% to 80 mol% of (meth)acrylamide units, the water-soluble polymer (2) contains a keto group-containing ethylenically unsaturated monomer unit. An aqueous solution of an electrical storage device separator binder containing 0.2 mol% to 10 mol% and 65 mol% to 99.7 mol% of (meth)acrylamide group-containing compound units, wherein the hydrazide has two or more hydrazide groups.

Description

Power storage device separator binder aqueous solution, power storage device separator slurry, power storage device separator, power storage device separator/electrode laminate, and power storage device.

This disclosure relates to a power storage device separator binder aqueous solution, a power storage device separator slurry, a power storage device separator, a power storage device separator/electrode laminate, and a power storage device.

In separators for electrical storage devices, a binder is used to maintain adhesion between the coating layer (heat-resistant layer) and the substrate.

The electrical storage device separator slurry contains a binder and a solvent. The present applicant is examining a method of using water-soluble poly(meth)acrylamide as a binder (Patent Document 1).

Patent Document 1: Japanese Patent Laid-Open No. 2018-026266

The problem to be solved by the present invention (1) is to provide an aqueous solution of an electrical storage device separator binder that can provide good non-conductive particle binding properties, adhesion, rate resistance, and output characteristics.

The problem to be solved by the present invention (2) is to provide an aqueous solution of an electrical storage device separator binder that can provide good heat shrinkage resistance, non-conductive particle adhesion, adhesion, rate resistance, and output characteristics.

The present inventors have discovered that the above problem can be solved by using specific ingredients.

By this disclosure, the following items are provided.

(Item 1)

As a power storage device separator binder aqueous solution,

The electrical storage device separator binder aqueous solution contains a water-soluble polymer (1) or a water-soluble polymer (2) and hydrazide,

The water-soluble polymer (1) contains 20 mol% to 80 mol% of N,N-dialkyl (meth)acrylamide units and 10 mol% to 80 mol% of (meth)acrylamide units,

The water-soluble polymer (2) contains 0.2 mol% to 10 mol% of keto group-containing ethylenically unsaturated monomer units and 65 mol% to 99.7 mol% of (meth)acrylamide group-containing compound units,

The hydrazide has two or more hydrazide groups.

Power storage device separator binder aqueous solution.

(Item 2)

The water-soluble polymer (1) is the electrical storage device separator binder aqueous solution described in the above item, wherein the unsaturated carboxylic acid and/or its salt unit is contained in an amount of less than 40 mol%.

(Item 3)

The water-soluble polymer (2) is the electrical storage device separator binder aqueous solution described in the above item, wherein the unsaturated carboxylic acid and/or its salt unit is contained in an amount of less than 30 mol%.

(Item 4)

As a power storage device separator slurry,

The electrical storage device separator slurry contains a water-soluble polymer (1), water and non-conductive particles, or contains a water-soluble polymer (2), hydrazide, water and non-conductive particles,

The water-soluble polymer (1) contains 20 mol% to 80 mol% of N,N-dialkyl (meth)acrylamide units and 10 mol% to 80 mol% of (meth)acrylamide units,

The water-soluble polymer (2) contains 0.2 mol% to 10 mol% of keto group-containing ethylenically unsaturated monomer units and 65 mol% to 99.7 mol% of (meth)acrylamide group-containing compound units,

The hydrazide has two or more hydrazide groups.

Power storage device separator slurry.

(Item 5)

A power storage device separator comprising the dried product of the power storage device separator slurry described in the above item on a substrate.

(Item 6)

An electrical storage device separator/electrode laminate comprising the dried product of the electrical storage device separator slurry described in the above item on the active material side of an electrode.

(Item 7)

An electrical storage device comprising the electrical storage device separator described in the above item and/or the electrical storage device separator/electrode laminate described in the above item.

In the present disclosure, one or more features described above may be provided in further combinations in addition to the specified combinations.

The electrical storage device separator binder aqueous solution of this embodiment (1) can provide good non-conductive particle binding properties, adhesion, rate resistance, and output characteristics.

The aqueous solution of the electrical storage device separator binder of this embodiment (2) can provide good heat shrinkage resistance, non-conductive particle binding properties, adhesion, rate resistance, and output characteristics.

Throughout the present disclosure, the numerical range of each physical property value, content, etc. can be set appropriately (for example, by selecting from the values described in each item below). Specifically, when A3, A2, and A1 (A3>A2>A1) is exemplified as the numerical value α, the range of the numerical value α is, for example, A3 or less, A2 or less, less than A3, less than A2, or more than A1. , A2 or more, greater than A1, greater than A2, A1 to A2 (A1 to A2 or less), A1 to A3, A2 to A3, A1 or more but less than A3, A1 or more but less than A2, A2 or more but less than A3, greater than A1 and less than A3. , greater than A1 but less than A2, greater than A2 but less than A3, greater than A1 but less than A3, greater than A1 but less than A2, greater than A2 and less than A3, etc.

In the present disclosure, each component, condition, value, etc. is not limited to what is specifically exemplified in the description of the present invention. As long as the problem to be solved by the present invention can be solved, each component, condition, value, etc. is not particularly limited.

“αβ amount (A/B)” means the β amount (α) of A relative to B 100α. Examples of α include mass%, mol%, and mass parts. The β amount includes, for example, content and usage amount.

“γ ratio (A/B)” means the γ ratio calculated by the formula “A÷B”. Examples of the γ ratio include mass ratio and molar ratio.

“(meth)acrylic” means “at least one selected from the group consisting of acrylic and methacryl.” “(meth)acrylate” means “at least one selected from the group consisting of acrylates and methacrylates.” “(meth)acryloyl” means “at least one selected from the group consisting of acryloyl and methacryloyl.”

Examples of alkyl groups include straight-chain alkyl groups, branched alkyl groups, and cycloalkyl groups.

Straight-chain alkyl groups include, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, and n-decamethyl group. etc. can be mentioned.

“Branched alkyl group” means a group in which at least one hydrogen atom of a straight-chain alkyl group is replaced by an alkyl group and does not have a cyclic structure.

Examples of branched alkyl groups include i-propyl group, diethylpentyl group, trimethylbutyl group, trimethylpentyl group, and trimethylhexyl group.

Examples of cycloalkyl groups include monocyclic cycloalkyl groups, cross-linked cycloalkyl groups, and condensed ring cycloalkyl groups. In addition, a cycloalkyl group in which at least one hydrogen atom of the cycloalkyl group is replaced by an alkyl group is also referred to as a cycloalkyl group.

In the present disclosure, “monocycle” means a cyclic structure formed by covalent bonds of carbon and having no crosslinked structure inside. “Condensed ring” means a cyclic structure in which two or more single rings share two atoms (that is, only one edge of each ring is shared (condensed) with each other). “Cross-exchange” refers to a cyclic structure in which two or more single rings share three or more atoms.

Examples of the monocyclic cycloalkyl group include cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclodecyl group, and 3,5,5-trimethylcyclohexyl group.

Examples of cross-linked cycloalkyl groups include tricyclodecyl group, adamantyl group, and norbornyl group.

[Power storage device separator binder aqueous solution: aqueous solution]

The present disclosure is an aqueous solution of an electrical storage device separator binder,

The electrical storage device separator binder aqueous solution contains a water-soluble polymer (1) or a water-soluble polymer (2) and hydrazide,

The water-soluble polymer (1) contains 20 mol% to 80 mol% of N,N-dialkyl (meth)acrylamide units and 10 mol% to 80 mol% of (meth)acrylamide units,

The water-soluble polymer (2) contains 0.2 mol% to 10 mol% of keto group-containing ethylenically unsaturated monomer units and 65 mol% to 99.7 mol% of (meth)acrylamide group-containing compound units,

The hydrazide has two or more hydrazide groups.

It relates to an aqueous solution of a power storage device separator binder.

In the present disclosure, “water-soluble polymer” means a concept that combines water-soluble polymer (1) and water-soluble polymer (2).

<Water-soluble polymer>

Water-soluble polymers may be used singly or in combinations of two or more.

In the present disclosure, “water-soluble” means that when 0.5 g of the compound is dissolved in 100 g of water at 25°C, the insoluble matter is less than 0.5 mass% (less than 2.5 mg).

If a polymer is not water soluble, it will not dissolve in water. Therefore, the polymer solution does not become an aqueous solution. As a result, the polymer does not contribute to slurry dispersion. Additionally, the required viscosity cannot be imparted to the slurry after the polymer is applied.

When 0.5 g of polymer is dissolved in 100 g of water, the insoluble content (water-soluble polymer) is, for example, less than 0.5 mass%, less than 0.4 mass%, less than 0.3 mass%, less than 0.2 mass%, less than 0.1 mass%, 0. Mass %, etc. can be mentioned.

(Compound containing (meth)acrylamide group)

(meth)acrylamide group-containing compounds may be used individually or in combination of two or more types.

In one embodiment, the (meth)acrylamide group-containing compound is represented by the following formula.

(In the formula, R ¹ represents a hydrogen atom or a methyl group.

R ² and R ³ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or an acetyl group, or R ² and R ³ combine to form a ring structure.

R ⁴ and R ⁵ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, a hydroxy group, a substituted or unsubstituted amino group, or an acetyl group)

Substituents include, for example, hydroxy groups, amino groups, and acetyl groups.

Examples of the ring structure include a morpholyl group.

The (meth)acrylamide group-containing compounds include, for example, (meth)acrylamide, N,N-dialkyl (meth)acrylamide, N-isopropyl (meth)acrylamide, and N,N-dimethylaminopropyl ( Meta)acrylamide, N-methylol (meth)acrylamide, maleic acid amide, (meth)acryloylmorpholine, hydroxyethyl (meth)acrylamide, etc. are mentioned.

(N,N-dialkyl (meth)acrylamide)

N,N-dialkyl (meth)acrylamide can be used individually or in combination of two or more types.

N,N-dialkyl (meth)acrylamide is, for example, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N-dipropyl (meth)acrylamide. , N,N-dibutyl (meth)acrylamide, etc.

The mol% content (N,N-dialkyl (meth)acrylamide unit/water-soluble polymer (1)) is, for example, 80 mol%, 75 mol%, 70 mol%, 65 mol%, 60 mol%, 55 mol. %, 50 mol%, 45 mol%, 40 mol%, 35 mol%, 30 mol%, 25 mol%, 20 mol%, etc. In one embodiment, the content is preferably 20 mol% to 80 mol%.

The mass% content (N,N-dialkyl (meth)acrylamide unit/water-soluble polymer (1)) is, for example, 80 mass%, 75 mass%, 70 mass%, 65 mass%, 60 mass%, 55 mass%. %, 50 mass%, 45 mass%, 40 mass%, 35 mass%, 30 mass%, 25 mass%, 20 mass%, etc. In one embodiment, the content is preferably 20% by mass to 80% by mass.

((meth)acrylamide)

Any of acrylamide alone, methacrylamide alone, or a combination of acrylamide and methacrylamide may be used.

The mol% content ((meth)acrylamide unit/water-soluble polymer (1)) is, for example, 80 mol%, 75 mol%, 70 mol%, 69.9 mol%, 65 mol%, 60 mol%, 55 mol%, Examples include 50 mol%, 45 mol%, 40 mol%, 39.9 mol%, 35 mol%, 30 mol%, 25 mol%, 24.9 mol%, 20 mol%, 15 mol%, 14.9 mol%, 10 mol%, etc. You can. In one embodiment, the content is preferably 10 mol% to 80 mol%.

The mass% content ((meth)acrylamide unit/water-soluble polymer (1)) is, for example, 80 mass%, 75 mass%, 70 mass%, 69.9 mass%, 65 mass%, 60 mass%, 55 mass%, 50 mass%, 45 mass%, 40 mass%, 39.9 mass%, 35 mass%, 30 mass%, 25 mass%, 24.9 mass%, 20 mass%, 15 mass%, 14.9 mass%, 10 mass%, etc. You can. In one embodiment, the content is preferably 10% by mass to 80% by mass.

The mol% content ((meth)acrylamide group-containing compound unit/water-soluble polymer (2)) is, for example, 99.7 mol%, 99.6 mol%, 99.5 mol%, 99.4 mol%, 99.3 mol%, 99.2 mol%, 99.1 mol%. Mol%, 99 mol%, 95 mol%, 90 mol%, 85 mol%, 80 mol%, 75 mol%, 70 mol%, 65 mol%, etc. are mentioned. In one embodiment, the content is preferably 65 mol% to 99.7 mol%, and more preferably 70 mol% to 99.7 mol%.

The mass% content ((meth)acrylamide group-containing compound unit/water-soluble polymer (2)) is, for example, 99.7 mass%, 99.6 mass%, 99.5 mass%, 99.4 mass%, 99.3 mass%, 99.2 mass%, 99.1 mass%. Mass %, 99 mass %, 95 mass %, 90 mass %, 85 mass %, 80 mass %, 75 mass %, 70 mass %, etc. are mentioned. In one embodiment, the content is preferably 70% by mass to 99.7% by mass.

(Keto group-containing ethylenically unsaturated monomer)

The keto group-containing ethylenically unsaturated monomer may be used individually or in combination of two or more types.

Keto group-containing ethylenically unsaturated monomers include, for example, diacetone (meth)acrylamide, acrolein, N-vinylformamide, vinyl methyl ketone, vinyl ethyl ketone, acetoacetoxyethyl (meth)acrylate, and acetoacetoxypropyl. (meth)acrylate, acetoacetoxybutyl (meth)acrylate, etc. can be mentioned.

The mol% content (keto group-containing ethylenically unsaturated monomer unit/water-soluble polymer (2)) is, for example, 10 mol%, 9.9 mol%, 9.7 mol%, 9.5 mol%, 9.3 mol%, 9.1 mol%, 9 mol. %, 8 mol%, 7 mol%, 6 mol%, 5 mol%, 4 mol%, 3 mol%, 2 mol%, 1.9 mol%, 1.7 mol%, 1.5 mol%, 1.4 mol%, 1.1 mol%, Examples include 1 mol%, 0.9 mol%, 0.7 mol%, 0.5 mol%, 0.3 mol%, 0.25 mol%, and 0.2 mol%. In one embodiment, the content is preferably 0.2 mol% to 10 mol%.

The mass % content (keto group-containing ethylenically unsaturated monomer unit/water-soluble polymer (2)) is, for example, 10 mass %, 9.9 mass %, 9.7 mass %, 9.5 mass %, 9.3 mass %, 9.1 mass %, 9 mass %. %, 8 mass%, 7 mass%, 6 mass%, 5 mass%, 4 mass%, 3 mass%, 2 mass%, 1.9 mass%, 1.7 mass%, 1.5 mass%, 1.4 mass%, 1.1 mass%, Examples include 1 mass%, 0.9 mass%, 0.7 mass%, 0.5 mass%, 0.3 mass%, 0.25 mass%, and 0.2 mass%. In one embodiment, the content is preferably 0.2% by mass to 10% by mass.

(Unsaturated carboxylic acid and/or its salt)

In one embodiment, the water-soluble polymer optionally includes a structural unit derived from an unsaturated carboxylic acid and/or a salt thereof.

Unsaturated carboxylic acids and/or their salts may be used individually or in combination of two or more.

Examples of unsaturated carboxylic acids include (meth)acrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid.

Examples of salts of unsaturated carboxylic acids include inorganic salts of unsaturated carboxylic acids and organic salts of unsaturated carboxylic acids.

Examples of inorganic salts of unsaturated carboxylic acids include sodium salts of unsaturated carboxylic acids, lithium salts of unsaturated carboxylic acids, and calcium salts of unsaturated carboxylic acids.

Examples of organic salts of unsaturated carboxylic acids include ammonium salts of unsaturated carboxylic acids and amine salts of unsaturated carboxylic acids.

The mol% content (unsaturated carboxylic acid and/or its salt unit/water-soluble polymer (1)) is, for example, 40 mol%, 35 mol%, 30 mol%, 25 mol%, 20 mol%, 15 mol%, 10 mol. %, 9 mol%, 7 mol%, 5 mol%, 4 mol%, 3 mol%, 2 mol%, 1 mol%, 0.9 mol%, 0.7 mol%, 0.5 mol%, 0.3 mol%, 0.1 mol%, Examples include 0.09 mol%, 0.05 mol%, 0.01 mol%, and 0 mol%. In one embodiment, the content is preferably 0 mol% or more and less than 40 mol%.

The mol% content (unsaturated carboxylic acid and/or its salt unit/water-soluble polymer (2)) is, for example, 30 mol%, 25 mol%, 20 mol%, 15 mol%, 10 mol%, 9 mol%, 7 mol. %, 5 mol%, 4 mol%, 3 mol%, 2 mol%, 1 mol%, 0.9 mol%, 0.7 mol%, 0.5 mol%, 0.3 mol%, 0.1 mol%, 0.09 mol%, 0.05 mol%, Examples include 0.01 mol% and 0 mol%. In one embodiment, the content is preferably 0 mol% to 30 mol%.

The mass% content (unsaturated carboxylic acid and/or its salt unit/water-soluble polymer (1)) is, for example, 40 mass%, 35 mass%, 30 mass%, 25 mass%, 20 mass%, 15 mass%, 10 mass%. %, 9 mass%, 7 mass%, 5 mass%, 4 mass%, 3 mass%, 2 mass%, 1 mass%, 0.9 mass%, 0.7 mass%, 0.5 mass%, 0.3 mass%, 0.1 mass%, Examples include 0.09 mass%, 0.05 mass%, 0.01 mass%, and 0 mass%. In one embodiment, the content is preferably 0% by mass or more and less than 40% by mass.

The mass% content (unsaturated carboxylic acid and/or its salt unit/water-soluble polymer (2)) is, for example, 40 mass%, 35 mass%, 30 mass%, 25 mass%, 20 mass%, 15 mass%, 10 mass%. %, 9 mass%, 7 mass%, 5 mass%, 4 mass%, 3 mass%, 2 mass%, 1 mass%, 0.9 mass%, 0.7 mass%, 0.5 mass%, 0.3 mass%, 0.1 mass%, Examples include 0.09 mass%, 0.05 mass%, 0.01 mass%, and 0 mass%. In one embodiment, the content is preferably 0% by mass to 40% by mass.

(Monomers other than any of the above: other ingredients)

The water-soluble polymer (1) may optionally contain a monomer (other component) unit that is not any of “N,N-dialkyl (meth)acrylamide, (meth)acrylamide, unsaturated carboxylic acid and/or salt thereof”. there is.

The water-soluble polymer (2) may optionally contain a monomer (other component) unit that is not any of “keto group-containing ethylenically unsaturated monomer, (meth)acrylamide group-containing compound, unsaturated carboxylic acid and/or salt thereof”. .

Other components may be used individually or in combination of two or more.

Other components include, for example, unsaturated sulfonic acid and/or its salt, polyfunctional monomer, unsaturated phosphoric acid and/or its salt, α,β-unsaturated nitrile, hydroxyl group-containing unsaturated carboxylic acid ester, hydroxyl group-free unsaturated carboxylic acid ester, conjugated diene, Vinyl ether, aromatic vinyl compounds, etc. can be mentioned.

Unsaturated sulfonic acids include, for example, α,β-ethylenically unsaturated sulfonic acids such as vinyl sulfonic acid, styrene sulfonic acid, and (meth)allyl sulfonic acid; (meth)acrylamide-t-butylsulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, 2-(meth)acrylamide-2-hydroxypropanesulfonic acid, 3-sulfopropane (meth)acrylic acid ester, Bis-(3-sulfopropyl)itaconate ester, etc. can be mentioned.

Examples of salts of unsaturated sulfonic acids include inorganic salts of unsaturated sulfonic acids and organic salts of unsaturated sulfonic acids.

Examples of inorganic salts of unsaturated sulfonic acids include sodium salts of unsaturated sulfonic acids, lithium salts of unsaturated sulfonic acids, and calcium salts of unsaturated sulfonic acids.

Organic salts of unsaturated sulfonic acids include, for example, ammonium salts of unsaturated sulfonic acids and amine salts of unsaturated sulfonic acids.

In the present disclosure, “compounds that are both (meth)acrylamide group-containing compounds and unsaturated sulfonic acids and/or their salts” mean “unsaturated sulfonic acids and/or their salts.”

The mol% content (unsaturated sulfonic acid and/or its salt unit/water-soluble polymer (1)) is, for example, 10 mol%, 9 mol%, 8 mol%, 7 mol%, 6 mol%, 5 mol%, 4 mol. %, 3 mol%, 2 mol%, 1 mol%, 0.9 mol%, 0.7 mol%, 0.5 mol%, 0.3 mol%, 0.1 mol%, 0.09 mol%, 0.07 mol%, 0.05 mol%, 0.04 mol%, Examples include 0.03 mol%, 0.025 mol%, 0.02 mol%, 0.01 mol%, and 0 mol%. In one embodiment, the content is preferably 0 mol% to 10 mol%, and more preferably 0.05 mol% to 2 mol%.

The mol% content (unsaturated sulfonic acid and/or its salt unit/water-soluble polymer (2)) is, for example, 10 mol%, 9 mol%, 8 mol%, 7 mol%, 6 mol%, 5 mol%, 4 mol. %, 3 mol%, 2 mol%, 1 mol%, 0.9 mol%, 0.7 mol%, 0.5 mol%, 0.3 mol%, 0.1 mol%, 0.09 mol%, 0.07 mol%, 0.05 mol%, 0.04 mol%, Examples include 0.03 mol%, 0.025 mol%, 0.02 mol%, 0.01 mol%, and 0 mol%. In one embodiment, the content is preferably 0 mol% to 10 mol%, and more preferably 0.05 mol% to 2 mol%.

The mass% content (unsaturated sulfonic acid and/or its salt unit/water-soluble polymer (1)) is, for example, 10% by mass, 9% by mass, 8% by mass, 7% by mass, 6% by mass, 5% by mass, 4% by mass. %, 3 mass %, 2 mass %, 1 mass %, 0.9 mass %, 0.7 mass %, 0.5 mass %, 0.3 mass %, 0.1 mass %, 0.09 mass %, 0.07 mass %, 0.05 mass %, 0.04 mass %, Examples include 0.03 mass%, 0.025 mass%, 0.02 mass%, 0.01 mass%, and 0 mass%. In one embodiment, the content is preferably 0% by mass to 10% by mass.

The mass% content (unsaturated sulfonic acid and/or its salt unit/water-soluble polymer (2)) is, for example, 10% by mass, 9% by mass, 8% by mass, 7% by mass, 6% by mass, 5% by mass, 4% by mass. %, 3 mass %, 2 mass %, 1 mass %, 0.9 mass %, 0.7 mass %, 0.5 mass %, 0.3 mass %, 0.1 mass %, 0.09 mass %, 0.07 mass %, 0.05 mass %, 0.04 mass %, Examples include 0.03 mass%, 0.025 mass%, 0.02 mass%, 0.01 mass%, and 0 mass%. In one embodiment, the content is preferably 0% by mass to 10% by mass.

“Polyfunctional monomer” means a monomer having two or more ethylenically unsaturated double bonds.

Examples of polyfunctional monomers include N,N'-alkylenebis(meth)acrylamide, tri(allyl group)-containing monomer, and tri((meth)acryloyl group)-containing triazine.

Examples of N,N'-alkylenebis(meth)acrylamide include N,N'-methylenebis(meth)acrylamide and N,N'-ethylenebis(meth)acrylamide.

Examples of tri(allyl group)-containing monomers include triallyl isocyanurate, triallyl trimellitate, triallylamine, and triallyl (meth)acrylamide.

Triazine containing tri((meth)acryloyl group) is, for example, 1,3,5-tri((meth)acryloyl)-1,3,5-triazine, 1,3,5-tri( (meth)acryloyl)hexahydro-1,3,5-triazine, etc. can be mentioned.

Unsaturated phosphoric acids include, for example, vinylphosphonic acid, vinyl phosphate, bis((meth)acryloxyethyl) phosphate, diphenyl-2-(meth)acryloyloxyethyl phosphate, and dibutyl-2-(meth)acrylic acid. Iloxyethyl phosphate, dioctyl-2-(meth)acryloyloxyethyl phosphate, monomethyl-2-(meth)acryloyloxyethyl phosphate, 3-(meth)acryloxy-2-hydroxypropane phosphate, etc. can be mentioned.

Examples of salts of unsaturated phosphoric acid include inorganic salts of unsaturated phosphoric acid and organic salts of unsaturated phosphoric acid.

Examples of the inorganic salt of unsaturated phosphoric acid include sodium salt of unsaturated phosphoric acid, lithium salt of unsaturated phosphoric acid, and calcium salt of unsaturated phosphoric acid.

Examples of organic salts of unsaturated phosphoric acid include ammonium salts of unsaturated phosphoric acids and amine salts of unsaturated phosphoric acids.

Examples of α,β-unsaturated nitrile include (meth)acrylonitrile, α-chloro(meth)acrylonitrile, α-ethyl(meth)acrylonitrile, and vinylidene cyanide.

The mol% content (α,β-unsaturated nitrile unit/water-soluble polymer (1)) is, for example, 20 mol%, 19 mol%, 17 mol%, 15 mol%, 13 mol%, 11 mol%, 10 mol%. , 9 mol%, 8 mol%, 7 mol%, 6 mol%, 5 mol%, 4 mol%, 3 mol%, 2 mol%, 1 mol%, 0 mol%, etc. In one embodiment, the content is preferably 0 mol% to 20 mol%.

The mol% content (α,β-unsaturated nitrile unit/water-soluble polymer (2)) is, for example, 20 mol%, 19 mol%, 17 mol%, 15 mol%, 13 mol%, 11 mol%, 10 mol%. , 9 mol%, 8 mol%, 7 mol%, 6 mol%, 5 mol%, 4 mol%, 3 mol%, 2 mol%, 1 mol%, 0 mol%, etc. In one embodiment, the content is preferably 0 mol% to 20 mol%.

The mass% content (α,β-unsaturated nitrile unit/water-soluble polymer (1)) is, for example, 20% by mass, 19% by mass, 17% by mass, 15% by mass, 13% by mass, 11% by mass, 10% by mass. , 9 mass%, 8 mass%, 7 mass%, 6 mass%, 5 mass%, 4 mass%, 3 mass%, 2 mass%, 1 mass%, 0 mass%, etc. In one embodiment, the content is preferably 0% by mass to 20% by mass.

The mass% content (α,β-unsaturated nitrile unit/water-soluble polymer (2)) is, for example, 20% by mass, 19% by mass, 17% by mass, 15% by mass, 13% by mass, 11% by mass, 10% by mass. , 9 mass%, 8 mass%, 7 mass%, 6 mass%, 5 mass%, 4 mass%, 3 mass%, 2 mass%, 1 mass%, 0 mass%, etc. In one embodiment, the content is preferably 0% by mass to 20% by mass.

Hydroxyl group-containing unsaturated carboxylic acid esters include, for example, 1-hydroxyethyl (meth)acrylic acid, 2-hydroxyethyl (meth)acrylic acid, 1-hydroxypropyl (meth)acrylic acid, 2-hydroxypropyl (meth)acrylic acid, (meth)acrylic acid 3-hydroxypropyl, (meth)acrylic acid 2-hydroxy-1-methylethyl, (meth)acrylic acid 1-hydroxy-2-methylethyl, (meth)acrylic acid 1-hydroxybutyl, (meth)acrylic acid ) 2-hydroxybutyl acrylic acid, 3-hydroxybutyl (meth)acrylic acid, 4-hydroxybutyl (meth)acrylic acid, 1-hydroxy-1-methyl-propyl (meth)acrylic acid, 2-hyde (meth)acrylic acid Roxy-1-methyl-propyl, (meth)acrylic acid 3-hydroxy-1-methyl-propyl, (meth)acrylic acid 1-ethyl-2-hydroxyethyl, (meth)acrylic acid 1-hydroxy-2-methyl- Propyl, (meth)acrylic acid 2-hydroxy-2-methyl-propyl, (meth)acrylic acid 3-hydroxy-2-methyl-propyl, (meth)acrylic acid 1,1-dimethyl-2-hydroxyethyl, etc. You can.

The mol% content (hydroxyl group-containing unsaturated carboxylic acid ester unit/water-soluble polymer (1)) is, for example, 20 mol%, 19 mol%, 17 mol%, 15 mol%, 13 mol%, 11 mol%, 10 mol%, Examples include 9 mol%, 8 mol%, 7 mol%, 6 mol%, 5 mol%, 4 mol%, 3 mol%, 2 mol%, 1 mol%, and 0 mol%. In one embodiment, the content is preferably 0 mol% to 20 mol%.

The mol% content (hydroxyl group-containing unsaturated carboxylic acid ester unit/water-soluble polymer (2)) is, for example, 20 mol%, 19 mol%, 17 mol%, 15 mol%, 13 mol%, 11 mol%, 10 mol%, Examples include 9 mol%, 8 mol%, 7 mol%, 6 mol%, 5 mol%, 4 mol%, 3 mol%, 2 mol%, 1 mol%, and 0 mol%. In one embodiment, the content is preferably 0 mol% to 20 mol%.

The mass% content (hydroxyl group-containing unsaturated carboxylic acid ester unit/water-soluble polymer (1)) is, for example, 20 mass%, 19 mass%, 17 mass%, 15 mass%, 13 mass%, 11 mass%, 10 mass%, Examples include 9 mass%, 8 mass%, 7 mass%, 6 mass%, 5 mass%, 4 mass%, 3 mass%, 2 mass%, 1 mass%, and 0 mass%. In one embodiment, the content is preferably 0% by mass to 20% by mass.

The mass% content (hydroxyl group-containing unsaturated carboxylic acid ester unit/water-soluble polymer (2)) is, for example, 20 mass%, 19 mass%, 17 mass%, 15 mass%, 13 mass%, 11 mass%, 10 mass%, Examples include 9 mass%, 8 mass%, 7 mass%, 6 mass%, 5 mass%, 4 mass%, 3 mass%, 2 mass%, 1 mass%, and 0 mass%. In one embodiment, the content is preferably 0% by mass to 20% by mass.

Examples of the hydroxyl group-free unsaturated carboxylic acid ester include hydroxyl group-free (meth)acrylic acid ester. Hydroxyl group-free (meth)acrylic acid esters include, for example, hydroxyl group-free straight-chain (meth)acrylic acid ester, hydroxyl group-free branched (meth)acrylic acid ester, hydroxyl group-free alicyclic (meth)acrylic acid ester, and hydroxyl group-free substituted (meth)acrylic acid ester. Acrylic acid ester, etc. can be mentioned.

Straight-chain (meth)acrylic acid esters that do not contain hydroxyl groups include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-amyl (meth)acrylate, Examples include hexyl (meth)acrylate, n-octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, and 2-methoxyethyl (meth)acrylate.

Branched (meth)acrylic acid esters that do not contain hydroxyl groups include, for example, i-propyl (meth)acrylate, i-butyl (meth)acrylate, i-amyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. there is.

Examples of the hydroxyl group-free alicyclic (meth)acrylic acid ester include cyclohexyl (meth)acrylate.

Conjugated dienes include, for example, 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, and substituted straight-chain conjugated pentadiene. , substituted and side chain conjugated hexadiene, etc.

Examples of vinyl ether include hydroxyalkyl vinyl ether and polyalkylene glycol monovinyl ether.

Examples of the hydroxyalkyl vinyl ether include straight-chain hydroxy alkyl vinyl ether, branched hydroxy alkyl vinyl ether, and hydroxycycloalkyl vinyl ether.

Examples of straight-chain hydroxy alkyl vinyl ether include 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, and 5-hydroxypentyl vinyl ether.

Examples of the hydroxy branched alkyl vinyl ether include 2-hydroxypropyl vinyl ether, 2-hydroxy-2-methylpropyl vinyl ether, and 4-hydroxy-2-methylbutyl vinyl ether.

Examples of the hydroxycycloalkyl vinyl ether include 4-hydroxycyclopentyl vinyl ether.

Examples of polyalkylene glycol monovinyl ether include polymethylene glycol monovinyl ether, polyethylene glycol monovinyl ether, and polypropylene glycol monovinyl ether.

Examples of aromatic vinyl compounds include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, chlorostyrene, and divinylbenzene.

Mass% content (other components (excluding unsaturated sulfonic acid and/or its salt, α,β-unsaturated nitrile, and hydroxyl group-containing unsaturated carboxylic acid ester) unit/water-soluble polymer (1)) is, for example, less than 10% by mass, 9 Less than % by mass, less than 7 mass%, less than 5 mass%, less than 4 mass%, less than 2 mass%, less than 1 mass%, less than 0.9 mass%, less than 0.7 mass%, less than 0.5 mass%, less than 0.4 mass%, 0.2 mass% Examples include less than mass %, less than 0.1 mass %, and 0 mass %.

The mass% content (other components (excluding unsaturated sulfonic acid and/or its salt, α,β-unsaturated nitrile, and hydroxyl group-containing unsaturated carboxylic acid ester) unit/water-soluble polymer (2)) is, for example, less than 10% by mass, 9 Less than % by mass, less than 7 mass%, less than 5 mass%, less than 4 mass%, less than 2 mass%, less than 1 mass%, less than 0.9 mass%, less than 0.7 mass%, less than 0.5 mass%, less than 0.4 mass%, 0.2 mass% Examples include less than mass %, less than 0.1 mass %, and 0 mass %.

Mol% content (other components (excluding unsaturated sulfonic acid and/or its salt, α,β-unsaturated nitrile, and hydroxyl group-containing unsaturated carboxylic acid ester) unit/water-soluble polymer (1)) is, for example, less than 10 mol%, 9 Less than mol%, less than 7 mol%, less than 5 mol%, less than 4 mol%, less than 3 mol%, less than 2 mol%, less than 1 mol%, less than 0.9 mol%, less than 0.7 mol%, less than 0.5 mol%, 0.4 Examples include less than mol%, less than 0.2 mol%, less than 0.1 mol%, and 0 mol%.

Mol% content (other components (excluding unsaturated sulfonic acid and/or its salt, α,β-unsaturated nitrile, and hydroxyl group-containing unsaturated carboxylic acid ester) unit/water-soluble polymer (2)) is, for example, less than 10 mol%, 9 Less than mol%, less than 7 mol%, less than 5 mol%, less than 4 mol%, less than 3 mol%, less than 2 mol%, less than 1 mol%, less than 0.9 mol%, less than 0.7 mol%, less than 0.5 mol%, 0.4 Examples include less than mol%, less than 0.2 mol%, less than 0.1 mol%, and 0 mol%.

<Manufacturing method (water-soluble polymer)>

The production method (water-soluble polymer) includes, for example, radical polymerization. In one embodiment, the polymerization temperature is preferably 50°C to 100°C. In one embodiment, the polymerization time is preferably 1 hour to 10 hours.

Examples of radical polymerization initiators include azo-based polymerization initiators, persulfates, and redox-based polymerization initiators.

Examples of the azo-based initiator include 2,2'-azobis-2-amidinopropane dihydrochloride.

Examples of persulfate include potassium persulfate and ammonium persulfate.

Redox-based polymerization initiators include, for example, combination systems (persulfate and reducing agent).

Examples of the reducing agent include sodium bisulfite.

The mass part usage (radical polymerization initiator/monomer group) is preferably 0.05 parts by mass to 5.0 parts by mass, and more preferably 0.1 parts by mass to 3.0 parts by mass.

Before the radical polymerization reaction and/or when water-soluble the obtained water-soluble polymer, etc., the pH of the reaction solution can be adjusted, preferably using a neutralizing agent. Preferable reasons include, for example, improvement in manufacturing stability. In that case, the pH is preferably 2 to 11. Neutralizing agents include, for example, ammonia, organic amines, potassium hydroxide, sodium hydroxide, and lithium hydroxide. Additionally, a metal ion encapsulant (ethylenediaminetetraacetic acid (EDTA) or its salt, etc.) can also be used for the same purpose.

<Physical properties, etc. (water-soluble polymer)>

Weight average molecular weight (Mw) (water-soluble polymer (1)) is, for example, 6 million, 5.5 million, 5 million, 4.5 million, 4 million, 3.5 million, 3 million, 2.5 million, 2 million, 1.5 million, 1 million. , 950,000, 900,000, 850,000, 800,000, 750,000, 700,000, 650,000, 600,000, 550,000, 500,000, 450,000, 400,000, 350,000, 300,000, 250,000, 200,000, 15 Examples include 10,000 and 100,000. In one embodiment, the weight average molecular weight is preferably 100,000 to 6 million, and more preferably 350,000 to 6 million.

Weight average molecular weight (Mw) (water-soluble polymer (2)) is, for example, 6 million, 5.5 million, 5 million, 4.5 million, 4 million, 3.5 million, 3 million, 2.5 million, 2 million, 1.5 million, 1 million. , 950,000, 900,000, 850,000, 800,000, 750,000, 700,000, 650,000, 600,000, 550,000, 500,000, 450,000, 400,000, 350,000, 300,000, 250,000, 200,000, 15 Examples include 10,000 and 100,000. In one embodiment, the weight average molecular weight is preferably 100,000 to 6 million, and more preferably 350,000 to 6 million.

The number average molecular weight (Mn) (water-soluble polymer (1)) is, for example, 6 million, 5.5 million, 5 million, 4.5 million, 4 million, 3.5 million, 3 million, 2.5 million, 2 million, 1.5 million, and 1 million. , 950,000, 900,000, 850,000, 800,000, 750,000, 700,000, 650,000, 600,000, 550,000, 500,000, 450,000, 400,000, 300,000, 200,000, 100,000, 50,000, 1 Only, etc. can be mentioned. In one embodiment, the number average molecular weight is preferably 10,000 or more.

The number average molecular weight (Mn) (water-soluble polymer (2)) is, for example, 6 million, 5.5 million, 5 million, 4.5 million, 4 million, 3.5 million, 3 million, 2.5 million, 2 million, 1.5 million, and 1 million. , 950,000, 900,000, 850,000, 800,000, 750,000, 700,000, 650,000, 600,000, 550,000, 500,000, 450,000, 400,000, 300,000, 200,000, 100,000, 50,000, 1 Only, etc. can be mentioned. In one embodiment, the number average molecular weight is preferably 10,000 or more.

The molecular weight distribution (Mw/Mn) of the water-soluble polymer (1) is, for example, 15, 14, 13, 11, 10, 9, 7.5, 5, 4, 3, 2.9, 2.5, 2, 1.5, 1.1, etc. You can. In one embodiment, the molecular weight distribution (Mw/Mn) is preferably 1.1 to 15.

The molecular weight distribution (Mw/Mn) of the water-soluble polymer (2) is, for example, 15, 14, 13, 11, 10, 9, 7.5, 5, 4, 3, 2.9, 2.5, 2, 1.5, 1.1, etc. You can. In one embodiment, the molecular weight distribution (Mw/Mn) is preferably 1.1 to 15.

Weight average molecular weight, number average molecular weight, and molecular weight distribution can be measured under the following conditions.

Measuring device: Tosoh Corporation product, GPC (model number: HLC-8220)

Column: TSKgel G2500PW _XL (Tosoh Co., Ltd. product), TSKgel G4000 (Tosoh Co., Ltd. product), SHODEX SB-806M-HQ (Showa Denko KK product)

·Eluent: 0.2M phosphate buffer/acetonitrile solution (90/10, PH8.0)

·Column temperature: 40℃

Calibration curve: standard polyethylene oxide-polyethylene glycol

· Measured concentration: 0.10% by mass (water-soluble polymer concentration)

·Measurement method: Measurement after filter filtration

Filter: Cellulose acetate cartridge filter (Tosoh Co., Ltd. product, Myshori Disk W-13-2, hole diameter 0.2㎛)

Type B viscosity (water-soluble polymer (1)/water=15 mass%/85 mass%) is, for example, 100,000 mPa·s, 90,000 mPa·s, 80,000 mPa·s, 70,000 mPa·s, 6 10,000 mPa·s, 50,000 mPa·s, 40,000 mPa·s, 30,000 mPa·s, 20,000 mPa·s, 10,000 mPa·s, 9000 mPa·s, 8000 mPa·s, 7000 mPa·s, 6000 mPa·s , 5000mPa·s, 4000mPa·s, 3000mPa·s, 2000mPa·s, 1000mPa·s, etc. In one embodiment, the type B viscosity is preferably 1,000 mPa·s to 100,000 mPa·s.

Type B viscosity (water-soluble polymer (2)/water=15 mass%/85 mass%) is, for example, 100,000 mPa·s, 90,000 mPa·s, 80,000 mPa·s, 70,000 mPa·s, 6 10,000 mPa·s, 50,000 mPa·s, 40,000 mPa·s, 30,000 mPa·s, 20,000 mPa·s, 10,000 mPa·s, 9000 mPa·s, 8000 mPa·s, 7000 mPa·s, 6000 mPa·s , 5000mPa·s, 4000mPa·s, 3000mPa·s, 2000mPa·s, 1000mPa·s, etc. In one embodiment, the type B viscosity is preferably 1,000 mPa·s to 100,000 mPa·s.

Type B viscosity can be measured under the following conditions.

·Solid content concentration: 15 mass%

·Measurement temperature: 25℃

· Type B viscometer: Toki Sangyo Co., Ltd. product name “Type B viscometer model BM”

·Viscosity 20,000∼100,000mPa·s: No.4 rotor used, rotation speed 6rpm

·Viscosity less than 20,000mPa·s: Use No.3 rotor, rotation speed 6rpm

The mass% content (water-soluble polymer (1)/electrical storage device separator binder aqueous solution) is, for example, 20% by mass, 19% by mass, 15% by mass, 14% by mass, 12% by mass, 10% by mass, 9% by mass, 7% by mass. Mass %, 6 mass %, 5 mass %, 4 mass %, 3 mass %, 2 mass %, 1 mass %, etc. are mentioned. In one embodiment, the content is preferably 1% by mass to 20% by mass.

The mass% content (water-soluble polymer (2)/electrical storage device separator binder aqueous solution) is, for example, 20% by mass, 19% by mass, 15% by mass, 14% by mass, 12% by mass, 10% by mass, 9% by mass, 7% by mass. Mass %, 6 mass %, 5 mass %, 4 mass %, 3 mass %, 2 mass %, 1 mass %, etc. are mentioned. In one embodiment, the content is preferably 1% by mass to 20% by mass.

<Water>

Examples of water include ultrapure water, pure water, distilled water, ion-exchanged water, and tap water.

The mass % content (water/electrical storage device separator binder aqueous solution) is, for example, 99.9 mass %, 99 mass %, 95 mass %, 90 mass %, 85 mass %, 80 mass %, etc. In one embodiment, the content is preferably 80% by mass to 99.9% by mass.

The mass ratio [water-soluble polymer (1)/water] is, for example, 0.25, 0.24, 0.22, 0.20, 0.18, 0.15, 0.12, 0.10, 0.09, 0.07, 0.05, etc. In one embodiment, the mass ratio is preferably 0.05 to 0.25.

The mass ratio [water-soluble polymer (2)/water] is, for example, 0.25, 0.24, 0.22, 0.20, 0.18, 0.15, 0.12, 0.10, 0.09, 0.07, 0.05, etc. In one embodiment, the mass ratio is preferably 0.05 to 0.25.

<Additives>

The electrical storage device separator binder aqueous solution may optionally contain an agent that does not fall under any of “water-soluble polymer (1), water-soluble polymer (2), and water” as an additive. Additives may be used individually or in combination of two or more.

Additives include, for example, dispersants, leveling agents, and antioxidants.

Dispersants include, for example, anionic dispersants, cationic dispersants, nonionic dispersants, and polymer dispersants.

Examples of the leveling agent include surfactants such as alkyl-based surfactants, silicone-based surfactants, fluorine-based surfactants, and metal-based surfactants. By using a surfactant, crawling that occurs during application can be prevented and the smoothness of the slurry layer (coating layer) can be improved.

Antioxidants include, for example, phenol compounds, hydroquinone compounds, organic phosphorus compounds, sulfur compounds, phenylenediamine compounds, and polymer-type phenol compounds.

“Polymeric phenol compound” means a polymer having a phenol structure. The weight average molecular weight (polymeric phenol compound) is preferably 200 to 1000, more preferably 600 to 700.

The mass part content (additive/water-soluble polymer (1)) is, for example, less than 5% by mass, less than 4% by mass, less than 2% by mass, less than 1% by mass, less than 0.9% by mass, less than 0.5% by mass, 0.4% by mass. Less than 0.2% by mass, less than 0.1% by mass, less than 0.09% by mass, less than 0.05% by mass, less than 0.04% by mass, less than 0.02% by mass, less than 0.01% by mass, 0% by mass, etc.

The mass part content (additive/water-soluble polymer (2)) is, for example, less than 5% by mass, less than 4% by mass, less than 2% by mass, less than 1% by mass, less than 0.9% by mass, less than 0.5% by mass, 0.4% by mass. Less than 0.2% by mass, less than 0.1% by mass, less than 0.09% by mass, less than 0.05% by mass, less than 0.04% by mass, less than 0.02% by mass, less than 0.01% by mass, 0% by mass, etc.

The mass% content (additive/electrical storage device separator binder aqueous solution) is, for example, less than 5% by mass, less than 4% by mass, less than 2% by mass, less than 1% by mass, less than 0.9% by mass, less than 0.5% by mass, 0.4% by mass. Less than 0.2% by mass, less than 0.1% by mass, less than 0.09% by mass, less than 0.05% by mass, less than 0.04% by mass, less than 0.02% by mass, less than 0.01% by mass, 0% by mass, etc.

<Physical properties of aqueous solution, etc.>

pH (power storage device separator binder aqueous solution) is, for example, 9, 8.9, 8.5, 8, 7.9, 7.5, 7, 6.9, 6.5, 6, 5.9, 5.5, 5, 4.9, 4.5, 4, 3.9, 3.6, 3.5. , 3.4, 3.2, 3.1, 3, etc. In one embodiment, the pH is preferably 3 to 9.

pH can be measured under the following conditions.

Measuring device: Glass electrode pH meter (e.g., manufactured by HORIBA, Ltd., product name “pH meter D-52”)

·Measurement temperature: 25℃

Examples of the usage form (electrical storage device separator binder aqueous solution) include battery separator binder aqueous solution, non-aqueous secondary battery separator binder aqueous solution, lithium ion battery separator binder aqueous solution, and sodium ion battery separator binder aqueous solution.

[Power storage device separator slurry: slurry]

The present disclosure is a power storage device separator slurry,

The electrical storage device separator slurry contains a water-soluble polymer (1), water and non-conductive particles, or contains a water-soluble polymer (2), hydrazide, water and non-conductive particles,

The water-soluble polymer (1) contains 20 mol% to 80 mol% of N,N-dialkyl (meth)acrylamide units and 10 mol% to 80 mol% of (meth)acrylamide units,

The water-soluble polymer (2) contains 0.2 mol% to 10 mol% of keto group-containing ethylenically unsaturated monomer units and 65 mol% to 99.7 mol% of (meth)acrylamide group-containing compound units,

The hydrazide has two or more hydrazide groups.

It relates to a power storage device separator slurry.

In the present disclosure, “slurry” means a suspension of liquid and solid particles.

Examples of the water-soluble polymer (1), water-soluble polymer (2), and water include those mentioned above.

The mass% content (water-soluble polymer (1)/slurry) is, for example, 10% by mass, 9% by mass, 8% by mass, 7% by mass, 6% by mass, 5% by mass, 4% by mass, 3% by mass, 2% by mass. Mass %, 1 mass %, 0.9 mass %, 0.7 mass %, 0.5 mass %, 0.3 mass %, 0.1 mass %, etc. are mentioned. In one embodiment, the content is preferably 0.1% by mass to 10% by mass.

The mass% content (water-soluble polymer (2)/slurry) is, for example, 10% by mass, 9% by mass, 8% by mass, 7% by mass, 6% by mass, 5% by mass, 4% by mass, 3% by mass, 2% by mass. Mass %, 1 mass %, 0.9 mass %, 0.7 mass %, 0.5 mass %, 0.3 mass %, 0.1 mass %, etc. are mentioned. In one embodiment, the content is preferably 0.1% by mass to 10% by mass.

The mass% content (water/slurry) is, for example, 80% by mass, 70% by mass, 65% by mass, 60% by mass, 55% by mass, 50% by mass, 45% by mass, 40% by mass, 35% by mass, 30% by mass. Mass %, etc. can be mentioned. In one embodiment, the content is preferably 30% by mass to 80% by mass.

pH (power storage device separator slurry) is, for example, 9, 8.9, 8.5, 8, 7.9, 7.5, 7, 6.9, 6.5, 6, 5.9, 5.5, 5, 4.9, 4.5, 4, 3.9, 3.6, 3.5, Examples include 3.4, 3.2, 3.1, and 3. In one embodiment, the pH is preferably 3 to 9.

<Non-conductive particles>

Non-conductive particles may be used individually or in combination of two or more types.

Non-conductive particles include, for example, oxide particles, nitride particles, covalent crystal particles, poorly soluble ionic crystal particles, and clay fine particles.

Oxide particles include, for example, aluminum oxide (alumina), hydrates of aluminum oxide (boehmite (AlOOH), gibbsite (Al(OH) ₃ )), bakelite, iron oxide, silicon oxide, and magnesium oxide. (magnesia), magnesium hydroxide, calcium oxide, titanium oxide (titania), BaTiO ₃ , ZrO, alumina-silica complex oxide, etc.

Nitride particles include, for example, aluminum nitride, silicon nitride, and boron nitride.

Examples of covalent crystal particles include silicon and diamond.

Examples of poorly soluble ionic crystal particles include barium sulfate, calcium fluoride, and barium fluoride.

Examples of clay fine particles include clay fine particles such as silica, talc, and montmorillonite.

In one embodiment, the non-conductive particles preferably include boehmite, alumina, magnesium oxide, and barium sulfate, and more preferably include boehmite. Preferred reasons include, for example, low water absorption and high heat resistance.

The average particle diameter (non-conductive particles) is, for example, 30 μm, 25 μm, 20 μm, 15 μm, 10 μm, 5 μm, 1 μm, 0.5 μm, 0.1 μm, 0.05 μm, 0.01 μm, etc. . In one embodiment, the average particle diameter is preferably 0.01 μm to 30 μm.

The mass% content (non-conductive particles/slurry) is, for example, 99.9% by mass, 95% by mass, 90% by mass, 80% by mass, 70% by mass, 60% by mass, 50% by mass, 40% by mass, 30% by mass. , 20 mass%, 10 mass%, 5 mass%, 1 mass%, 0.5 mass%, 0.2 mass%, 0.1 mass%, etc. In one embodiment, the content is preferably 0.1 mass% to 99.9 mass%.

The mass part content (water-soluble polymer (1)/non-conductive particles) is, for example, 15 parts by mass, 14 parts by mass, 13 parts by mass, 12 parts by mass, 11 parts by mass, 10 parts by mass, 9 parts by mass, and 8 parts by mass. , 7 parts by mass, 6 parts by mass, 5 parts by mass, 4 parts by mass, 3 parts by mass, 2 parts by mass, 1.5 parts by mass, 1 part by mass, etc. In one embodiment, the content is preferably 1 part by mass to 15 parts by mass, more preferably 1.5 parts by mass to 14 parts by mass, and still more preferably 2 parts by mass to 12 parts by mass. There can be wealth.

The mass part content (water-soluble polymer (2)/non-conductive particles) is, for example, 15 parts by mass, 14 parts by mass, 13 parts by mass, 12 parts by mass, 11 parts by mass, 10 parts by mass, 9 parts by mass, and 8 parts by mass. , 7 parts by mass, 6 parts by mass, 5 parts by mass, 4 parts by mass, 3 parts by mass, 2 parts by mass, 1.5 parts by mass, 1 part by mass, etc. In one embodiment, the content is preferably 1 part by mass to 15 parts by mass, more preferably 1.5 parts by mass to 14 parts by mass, and still more preferably 2 parts by mass to 12 parts by mass. There can be wealth.

<Slurry viscosity adjustment solvent>

The slurry viscosity adjustment solvent may be used individually or in combination of two or more.

Slurry viscosity adjustment solvents include, for example, amide solvents, hydrocarbon solvents, alcohol solvents, ketone solvents, ether solvents, ester solvents, amine solvents, lactone solvents, sulfoxide/sulfone solvents, and water.

Examples of the amide solvent include N-methylpyrrolidone, dimethylformamide, and N,N-dimethylacetamide.

Examples of hydrocarbon solvents include toluene, xylene, n-dodecane, and tetralin.

Examples of alcohol solvents include methanol, ethanol, 2-propanol, isopropyl alcohol, 2-ethyl-1-hexanol, 1-nonanol, and lauryl alcohol.

Examples of ketone solvents include acetone, methyl ethyl ketone, cyclohexanone, phorone, acetophenone, and isophorone.

Examples of ether solvents include dioxane and tetrahydrofuran (THF).

Examples of the ester solvent include benzyl acetate, isopentyl butyrate, methyl lactate, ethyl lactate, and butyl lactate.

Examples of amine solvents include o-toluidine, m-toluidine, and p-toluidine.

Examples of the lactone solvent include γ-butyrolactone and δ-butyrolactone.

Examples of sulfoxide/sulfone solvents include dimethyl sulfoxide and sulfolane.

In one embodiment, the slurry viscosity adjustment solvent is preferably N-methylpyrrolidone. Preferable reasons include, for example, improvement in coating workability.

The mass% content (slurry viscosity adjustment solvent/slurry) is, for example, 10% by mass, 9% by mass, 8% by mass, 7% by mass, 6% by mass, 5% by mass, 4% by mass, 3% by mass, 2% by mass. %, 1 mass%, 0.5 mass%, 0.1 mass%, 0 mass%, etc. are mentioned. In one embodiment, the content is preferably 0% by mass to 10% by mass.

<Additives>

The slurry may contain additives that do not correspond to any of the water-soluble polymer (1), water-soluble polymer (2), water, non-conductive particles, and a slurry viscosity adjustment solvent. Additives include, for example, those mentioned above.

The mass part content (additive/water-soluble polymer (1)) is, for example, 0 parts by mass to 5 parts by mass, less than 1 part by mass, less than 0.1 part by mass, less than 0.01 part by mass, 0 parts by mass, etc.

The mass part content (additive/water-soluble polymer (2)) is, for example, 0 parts by mass to 5 parts by mass, less than 1 part by mass, less than 0.1 part by mass, less than 0.01 part by mass, 0 parts by mass, etc.

The mass part content (additive/non-conductive particles) is, for example, 0 parts by mass to 5 parts by mass, less than 1 part by mass, less than 0.1 part by mass, less than 0.01 part by mass, 0 parts by mass, etc.

By mixing the above agents, a slurry can be prepared.

Mixing means (slurry) include, for example, a ball mill, sand mill, pigment disperser, mortar machine, ultrasonic disperser, homogenizer, planetary mixer, Hobart mixer, etc. .

The usage form (electrical storage device separator slurry) includes, for example, electric storage device separator slurry, battery separator slurry, non-aqueous secondary battery separator slurry, lithium ion battery separator slurry, sodium ion battery separator slurry, etc.

[Power storage device separator: separator]

This disclosure relates to a power storage device separator comprising the dried product of the power storage device separator slurry on a substrate.

Examples of the substrate include a porous polyolefin resin substrate and a plastic nonwoven fabric.

(Porous polyolefin resin base material)

“Porous polyolefin resin substrate” means a microporous film containing 50% by mass or more of resin such as polyolefin and mixtures or copolymers thereof.

Polyolefin resin may be used individually or in combination of two or more types. Examples of polyolefin resins include homopolymers and copolymers such as ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene.

The three-dimensional structure (polyolefin resin) includes, for example, isotactic, syndiotactic, and atactic.

In one embodiment, the polyolefin resin preferably includes high-density polyethylene, and more preferably includes high-density polyethylene and polypropylene.

In one embodiment, the mass% content (polyolefin resin/base material) is preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, and further. Preferably it is 70 mass% to 100 mass%. Preferable reasons include, for example, improvement in shutdown performance.

The porous polyolefin resin substrate may optionally contain fillers and fiber compounds. Strength, hardness, and heat shrinkage (porous polyolefin resin substrate) can be controlled by fillers and fiber compounds.

The porous polyolefin resin substrate may be surface treated as needed.

Surface treatment includes, for example, coating treatment, electron beam treatment, and plasma treatment.

In one embodiment, the surface treatment preferably includes coating treatment with a polar group-containing polymer. By the coating treatment, the electrolyte impregnability and adhesion to the dried slurry can be improved. Polar groups include, for example, carboxylic acid groups, hydroxyl groups, and sulfonic acid groups.

In one embodiment, the thickness (porous polyolefin resin substrate) is preferably 2 μm to 100 μm, and more preferably 5 μm to 50 μm.

(Plastic non-woven fabric)

Examples of nonwoven fabrics made of plastic include nonwoven fabrics composed only of synthetic fibers.

Materials (synthetic fibers) include, for example, polyolefin-based resin, polyester-based resin, acrylonitrile-based resin, polyamide-based resin, polyvinyl acetate-based resin, ethylene-vinyl acetate copolymer resin, acrylic resin, and polyvinyl chloride. -based resin, polyvinylidene chloride-based resin, polyvinyl ether-based resin, polyvinyl ketone-based resin, polyether-based resin, polyvinyl alcohol-based resin, diene-based resin, polyurethane-based resin, phenol-based resin, melamine-based resin, furan. -based resin, urea-based resin, aniline-based resin, unsaturated polyester-based resin, alkyd resin, fluorine-based resin, silicone-based resin, polyamideimide-based resin, polyphenylene sulfide-based resin, polyimide-based resin, polycarbonate-based resin, polya Zomethine-based resin, polyesteramide resin, polyetheretherketone-based resin, poly-p-phenylenebenzobisoxazole resin, polybenzimidazole-based resin, and ethylene-vinyl alcohol copolymer-based resin.

Examples of polyolefin-based resins include polypropylene, polyethylene, polymethylpentene, ethylene-vinyl alcohol copolymer, and olefin-based copolymer.

Polyester-based resins include, for example, polyethylene terephthalate (PET)-based resin, polybutylene terephthalate (PBT)-based resin, polytrimethylene terephthalate (PPT)-based resin, polyethylene naphthalate (PEN)-based resin, and polyester. Butylene naphthalate-based resin, polyethylene isonaphthalate-based resin, wholly aromatic polyester-based resin, etc. can be mentioned.

Acrylonitrile-based resins include, for example, polyacrylonitrile, copolymers of acrylonitrile with (meth)acrylic acid derivatives, vinyl acetate, etc.

Examples of polyamide resins include aliphatic polyamide, wholly aromatic polyamide, and semi-aromatic polyamide.

Examples of aliphatic polyamides include nylon.

The wholly aromatic polyamide includes, for example, poly-p-phenylene terephthalamide, poly-p-phenylene terephthalamide-3,4-diphenyl ether terephthalamide, and poly-m-phenyleneisophthalamide. You can.

“Semi-aromatic polyamide” refers to a polyamide in which a part of the main chain of the aromatic polyamide is a fatty chain.

Fibers (plastic non-woven fabric) may optionally contain fibers other than synthetic resin fibers.

Fibers other than synthetic resin fibers include, for example, solvent-spun cellulose, fibrils of solvent-spun cellulose, regenerated cellulose, fibrillates of regenerated cellulose, natural cellulose fibers, pulp products of natural cellulose fibers, and fibrillates of natural cellulose fibers. , inorganic fibers, etc.

The mass% content (fibers/nonwovens other than synthetic fibers) is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less. there is.

Types (fibers) include, for example, single fibers and composite fibers.

“Short fiber” means a fiber made of a single resin. “Composite fiber” means a fiber made of two or more types of resin.

Examples of composite fibers include sheath-core type, eccentric type, side-by-side type, sea-island type, orange type, and multi-bimetal type.

In one embodiment, the average fiber diameter (plastic nonwoven fabric) is preferably 1 μm to 15 μm, and more preferably 1 μm to 10 μm.

In the present disclosure, “average fiber diameter” means the average value of the fiber diameters of 20 fibers randomly selected from scanning electron microscope photographs.

In one embodiment, the average pore diameter (plastic nonwoven fabric) is preferably 1 μm to 20 μm, more preferably 3 μm to 20 μm, and even more preferably 5 μm to 20 μm. It can be 20㎛.

In the present disclosure, “pore diameter” means the width of the gap between fibers. “Average pore diameter” refers to the average value of the pore diameter of 20 fibers randomly selected from scanning electron microscope photographs.

The thickness (plastic nonwoven fabric) is preferably 5 μm to 25 μm, and more preferably 5 μm to 15 μm. Preferable reasons include, for example, that a separator with low internal resistance can be obtained by reducing the thickness.

<Manufacturing method (electrical storage device separator)>

Examples of the manufacturing method (electrical storage device separator) include a method including the following steps.

Application process: Apply power storage device separator slurry to one or both sides of the substrate.

Drying process: Drying the applied power storage device separator slurry

(Application process)

Application methods include, for example, a coating method, a printing method, a transfer method, and an immersion method.

Application methods include, for example, blade, rod, reverse roll, lip, die, curtain, air knife, etc.

Printing methods include, for example, flexo, screen, offset, gravure, and inkjet.

Transfer methods include, for example, roll transfer and film transfer.

Examples of the immersion method include dipping.

(drying process)

Drying methods include, for example, blow drying (warm air, hot air, low humidity air, etc.), irradiation drying (infrared rays, far infrared rays, electron beams, etc.), vacuum drying, etc.

The drying temperature is preferably 40°C to 90°C, and more preferably 50°C to 80°C.

The drying time is preferably 5 seconds to 3 minutes, and more preferably 15 seconds to 2 minutes.

The manufacturing method (electrical storage device separator) may optionally include a press process.

Press means include, for example, a mold press, roll press, etc.

Usage forms (electrical storage device separators) include, for example, battery separators, non-aqueous secondary battery separators, lithium ion battery separators, and sodium ion battery separators.

[Power storage device separator/electrode laminate: separator/electrode laminate]

This disclosure relates to a power storage device separator/electrode laminate comprising the dried product of the power storage device separator slurry on the active material side of the electrode. The electrical storage device separator/electrode laminate can be obtained by applying the electrical storage device separator slurry to an electrode and drying it.

Examples of electrodes used when manufacturing an electrical storage device separator/electrode laminate include various known electrodes.

The manufacturing method (electrical storage device separator/electrode laminate) includes, for example, a method including the following steps.

(1) Process of applying slurry containing electrode materials to the current collector

(2) Process of drying the slurry containing electrode materials

(3) Process of pressing the dried slurry containing electrode materials

(4) A process of applying the electricity storage device separator slurry to the dried product of the slurry containing electrode materials.

(5) Process of drying the power storage device separator slurry

Examples of the application method, drying method, and pressing method include the above methods.

The usage form (electrical storage device separator/electrode laminate) is, for example, battery separator/electrode laminate, battery separator/negative electrode laminate, battery separator/positive electrode laminate, non-aqueous secondary battery separator/electrode laminate, non-aqueous secondary battery separator/electrode laminate. Secondary battery separator/negative electrode laminate, non-aqueous secondary battery separator/positive electrode laminate, lithium ion battery separator/electrode laminate, lithium ion battery separator/negative electrode laminate, lithium ion battery separator/positive electrode laminate, sodium ion battery. A separator/electrode laminate, a sodium ion battery separator/negative electrode laminate, a sodium ion battery separator/positive electrode laminate, etc. can be mentioned.

[Power storage device]

The present disclosure relates to an electrical storage device including the electrical storage device separator and/or the electrical storage device separator/electrode laminate.

(electrolyte)

A power storage device contains an electrolyte solution. Examples of the electrolyte solution include a solution obtained by dissolving a supporting electrolyte in a non-aqueous solvent.

Non-aqueous solvents may be used individually or in combination of two or more.

Non-aqueous solvents include, for example, linear carbonate solvents, cyclic carbonate solvents, linear ether solvents, cyclic ether solvents, linear ester solvents, cyclic ester solvents, and acetonitrile.

Examples of linear carbonate solvents include diethyl carbonate, dimethyl carbonate, and ethylmethyl carbonate.

Examples of cyclic carbonate solvents include ethylene carbonate, propylene carbonate, and butylene carbonate.

Examples of linear ether solvents include 1,2-dimethoxyethane.

Examples of cyclic ether solvents include tetrahydrofuran, 2-methyltetrahydrofuran, sulfolane, and 1,3-dioxolane.

Examples of linear ester solvents include methyl formate, methyl acetate, and methyl propionate.

Examples of cyclic ester solvents include γ-butyrolactone and γ-valerolactone.

In one embodiment, the non-aqueous solvent preferably includes a combination of cyclic carbonate and linear carbonate.

The supporting electrolyte may be used individually or in combination of two or more types.

Examples of the supporting electrolyte include lithium salt. Lithium salts are, for example, LiPF ₆ , LiAsF ₆ , LiBF ₄ , LiSbF ₆ , LiAlCl ₄ , LiClO ₄ , CF ₃ SO ₃ Li, C ₄ F ₉ SO ₃ Li, CF ₃ COOLi, (CF ₃ CO) ₂ NLi , (CF ₃ SO ₂ ) ₂ NLi, (C ₂ F ₅ SO ₂ ) NLi, etc. In one embodiment, the supporting electrolyte preferably includes LiPF ₆ , LiClO ₄ , and CF ₃ SO ₃ Li. Preferable reasons include, for example, that the conductivity of lithium ions can be increased.

In one embodiment, the non-aqueous electrolyte solution may optionally contain a film former. Film forming agents may be used individually or in combination of two or more.

Film forming agents include, for example, carbonates, alkenesulfides, sultones, and acid anhydrides.

Carbonates include, for example, vinylene carbonate, vinylethylene carbonate, vinylethyl carbonate, methylphenyl carbonate, fluoroethylene carbonate, and difluoroethylene carbonate.

Examples of alkene sulfide include ethylene sulfide and propylene sulfide.

Examples of sultone include 1,3-propane sultone and 1,4-butane sultone.

Examples of acid anhydrides include maleic acid anhydride and succinic acid anhydride.

In one embodiment, the mass % content (film forming agent/electrolyte total amount) is preferably 10 mass % or less, more preferably 8 mass % or less, and even more preferably 5 mass % or less. Examples include mass % or less, and particularly preferably 2 mass % or less.

The form (electrical storage device) includes, for example, a cylinder type with a sheet electrode and a separator in a spiral shape, a cylinder type with an inside-out structure combining a pellet electrode and a separator, and a coin type with a stack of pellet electrodes and a separator. .

The manufacturing method (electrical storage device) includes, for example, the method described in Japanese Patent Application Laid-Open No. 2013-089437. A battery can be manufactured by placing a negative electrode on an external case, placing an electrolyte and a separator on it, further raising the positive electrode to face the negative electrode, and fixing it with a gasket and a sealing plate.

Use forms (electrical storage devices) include, for example, batteries, non-aqueous secondary batteries, lithium ion batteries, and sodium ion batteries.

(Example)

Below, the present invention will be described in detail through examples and comparative examples. However, the description of the preferred embodiment and the following examples are provided for illustrative purposes only and are not provided for the purpose of limiting the scope of the patent claims. In addition, in each Example and Comparative Example, unless otherwise specified, values such as parts and % are based on mass.

Example (1)-1-1 Preparation (electrical storage device separator binder aqueous solution)

In a reaction device equipped with a stirrer, thermometer, reflux cooling pipe, and nitrogen gas inlet pipe, 1440 g of ion-exchanged water, 178.0 g (1.80 mol) of dimethylacrylamide, 50.7 g (0.36 mol) of 50% acrylamide aqueous solution, and 21.6 g of 80% acrylic acid. g (0.24 mol) and 0.36 g (0.002 mol) of sodium methallylsulfonate were added, oxygen in the reaction system was removed by passing nitrogen gas, and the temperature was raised to 50°C. Add 2.2 g of 2,2'-azobis-2-amidinopropane dihydrochloride (NIPPOH CHEMICALS CO., LTD., product name "NC-32") and 22 g of ion-exchanged water. Then, the temperature was raised to 80°C and reaction was performed for 3 hours. After that, 18.0 g (0.22 mol) of 48% sodium hydroxide aqueous solution was added as a neutralizing agent, stirred, and ion-exchanged water was added so that the solid content concentration was 13%, thereby obtaining an aqueous solution of an electrical storage device separator binder. There was no water-insoluble content of the polymer.

In Example (1)-1 other than Example (1)-1-1, the monomer composition of Example (1)-1-1 was changed to that shown in the table below. In the same manner as 1-1, an aqueous solution of an electrical storage device separator binder was prepared.

Comparative example (1)-1-1

In a reaction device equipped with a stirrer, thermometer, reflux cooling pipe, and nitrogen gas inlet pipe, 1250 g of ion-exchanged water, 392.0 g (2.76 mol) of 50% acrylamide aqueous solution, 27.6 g (0.31 mol) of 80% acrylic acid, and sodium methallylsulfonate. 0.46 g (0.003 mol) was added, nitrogen gas was passed through it to remove oxygen in the reaction system, and the temperature was raised to 50°C. 2.2 g of 2,2'-azobis-2-amidinopropane dihydrochloride (Nippo Chemical Co., Ltd. product name "NC-32") and 22 g of ion exchanged water were added thereto, heated to 80°C, and incubated for 3 hours. The reaction was carried out. After that, 23.0 g (0.28 mol) of 48% sodium hydroxide aqueous solution was added as a neutralizing agent, stirred, and ion-exchanged water was added so that the solid content concentration was 13%, thereby obtaining an aqueous solution of an electrical storage device separator binder.

In Comparative Example (1)-1 other than Comparative Example (1)-1-1, the monomer composition of Comparative Example (1)-1-1 was changed to that shown in the table below. In the same manner as 1-1, an aqueous solution of an electrical storage device separator binder was prepared.

[Table (1)-1]

·DMAA: N,N-dimethylacrylamide (KJ Chemicals Corporation product, “DMAA”)

·DEAA: N,N-diethylacrylamide

·AM: Acrylamide (Mitsubishi Chemical Corporation product, “50% acrylamide”)

·MAM: Methacrylamide

·AA: Acrylic acid (OSAKA ORGANIC CHEMICAL INDUSTRY LTD. product, “80% acrylic acid”)

・MAA: Methacrylic acid (Mitsubishi Chemical Co., Ltd. product, “methacrylic acid”)

AN: Acrylonitrile (Mitsubishi Chemical Co., Ltd. product, “Acrylonitrile”)

・HEA: 2-hydroxyethyl acrylate (Osaka Organic Chemical Industry Co., Ltd. product, “HEA”)

SMAS: Sodium methallyl sulfonate

NaOH: Sodium hydroxide (KANTO CHEMICAL CO., INC., “48% sodium hydroxide solution”)

Preparation Example (2)-1 Preparation (Water-soluble polymer (2))

In a reaction device equipped with a stirrer, thermometer, reflux cooling pipe, and nitrogen gas inlet pipe, 1300 g of ion-exchanged water, 5.4 g (0.03 mol) of diacetone acrylamide, 447.1 g (3.14 mol) of 50% acrylamide aqueous solution, and methallyl sulfonic acid. 0.50 g (0.003 mol) of sodium was added, oxygen in the reaction system was removed by passing nitrogen gas, and the temperature was raised to 50°C. 2.3 g of 2,2'-azobis-2-amidinopropane dihydrochloride (Nippo Chemical Co., Ltd. product name "NC-32") and 23 g of ion-exchanged water were added thereto, and the temperature was raised to 80°C for 3 hours. The reaction was carried out. After that, ion-exchanged water was added so that the solid content concentration was 13%, and an aqueous polymer solution was obtained. There was no water-insoluble content of the polymer.

Production Examples (2)-2 to (2)-3 were the same as Production Example (2)-1 except that the monomer composition in Production Example (2)-1 was changed to that shown in the table below, and polymer An aqueous solution was prepared.

Manufacturing example (2)-4

In a reaction device equipped with a stirrer, thermometer, reflux cooling pipe, and nitrogen gas inlet pipe, 1400 g of ion-exchanged water, 4.3 g (0.03 mol) of diacetone acrylamide, 125.2 g (0.88 mol) of 50% acrylamide aqueous solution, and dimethyl acrylamide. 135.1 g (1.36 mol), 22.7 g (0.25 mol) of 80% acrylic acid, and 0.40 g (0.003 mol) of sodium methallylsulfonate were added, oxygen in the reaction system was removed by passing nitrogen gas, and the temperature was raised to 50°C. 2.2 g of 2,2'-azobis-2-amidinopropane dihydrochloride (Nippo Chemical Co., Ltd. product name "NC-32") and 22 g of ion exchanged water were added thereto, heated to 80°C, and incubated for 3 hours. The reaction was carried out. After that, 18.9 g (0.23 mol) of 48% sodium hydroxide aqueous solution was added as a neutralizing agent, stirred, and ion-exchanged water was added so that the solid content concentration was 13%, thereby obtaining an aqueous polymer solution. There was no water-insoluble content of the polymer.

Production Examples (2)-5 to (2)-7 were the same as Production Example (2)-4 except that the monomer composition in Production Example (2)-4 was changed to that shown in the table below, and polymer An aqueous solution was prepared.

Comparative Manufacturing Example (2)-1

Into a reaction device equipped with a stirrer, thermometer, reflux cooling pipe, and nitrogen gas inlet pipe, 1290 g of ion-exchanged water, 458.3 g (3.22 mol) of 50% acrylamide aqueous solution, and 0.26 g (0.002 mol) of sodium methallylsulfonate were added, and nitrogen After gas was passed through the reaction system to remove oxygen, the temperature was raised to 50°C. 2.3 g of 2,2'-azobis-2-amidinopropane dihydrochloride (Nippo Chemical Co., Ltd. product name "NC-32") and 23 g of ion-exchanged water were added thereto, and the temperature was raised to 80°C for 3 hours. The reaction was carried out. After that, ion-exchanged water was added so that the solid content concentration was 13%, and an aqueous polymer solution was obtained. There was no water-insoluble content of the polymer.

In Comparative Preparation Example (2)-2, an aqueous polymer solution was prepared in the same manner as Comparative Preparation Example (2)-1, except that the monomer composition in Comparative Preparation Example (2)-1 was changed to that shown in the table below. did.

Comparative Manufacturing Example (2)-3

In a reaction device equipped with a stirrer, thermometer, reflux cooling pipe, and nitrogen gas inlet pipe, 1,190 g of ion-exchanged water, 33.2 g (0.20 mol) of diacetone acrylamide, 181.2 g (1.27 mol) of 50% acrylamide aqueous solution, and 80% acrylic acid. 88.4 g (0.98 mol) and 0.19 g (0.001 mol) of sodium methallylsulfonate were added, oxygen in the reaction system was removed by passing nitrogen gas, and the temperature was raised to 50°C. 1.9 g of 2,2'-azobis-2-amidinopropane dihydrochloride (Nippo Chemical Co., Ltd., product name "NC-32") and 19 g of ion-exchanged water were added thereto, and the temperature was raised to 80°C for 3 hours. The reaction was carried out. After that, 73.6 g (0.88 mol) of 48% sodium hydroxide aqueous solution was added as a neutralizing agent, stirred, and ion-exchanged water was added so that the solid content concentration was 13%, thereby obtaining an aqueous polymer solution. There was no water-insoluble content of the polymer.

[Table (2)-1]

DAAM: Diacetone acrylamide

・AM: Acrylamide (Mitsubishi Chemical Co., Ltd. product, “50% acrylamide”)

·DMAA: N,N-dimethylacrylamide (KJ Chemicals Co., Ltd. product, “DMAA”)

・AA: Acrylic acid (Osaka Organic Chemical Co., Ltd. product, “80% acrylic acid”)

・MAA: Methacrylic acid (Mitsubishi Chemical Co., Ltd. product, “methacrylic acid”)

AN: Acrylonitrile (Mitsubishi Chemical Co., Ltd. product, “Acrylonitrile”)

・HEA: 2-hydroxyethyl acrylate (Osaka Organic Chemical Industry Co., Ltd. product, “HEA”)

SMAS: Sodium methallyl sulfonate

・NaOH: Sodium hydroxide (Kanto Chemical Co., Ltd. product, “48% sodium hydroxide solution”)

Example (2)-1-1 Preparation (electrical storage device separator binder aqueous solution)

100 parts by mass of the water-soluble polymer (2) obtained in Production Example (2)-1, in terms of solid content, and 0.50 parts by mass of adipic acid dihydrazide were mixed at 25°C for 0.5 hours to obtain a uniform electrical storage device separator binder aqueous solution. The viscosity of the obtained electrical storage device separator binder aqueous solution was measured with a B-type viscometer.

Example (2)-1 other than Example (2)-1-1 and Comparative Example (2)-1 were the same as Example (2)-1-1 except for the changes shown in the table below. , an electrical storage device separator binder aqueous solution was prepared, and the viscosity was measured with a B-type viscometer.

[Table (2)-2]

·ADH: Adipic acid dihydrazide

·SDH: Succinic acid dihydrazide

The measurement conditions (B type viscosity) are as follows.

·Solid content concentration: 15 mass%

·Measurement temperature: 25℃

· For viscosity 20,000 to 100,000 mPa·s: Use No.4 rotor, rotation speed 6 rpm

·If viscosity is less than 20,000mPa·s: Use No.3 rotor, rotation speed 6rpm

The measurement conditions (weight average molecular weight) are as follows.

Measuring device: Tosoh Co., Ltd. product, GPC (model number: HLC-8220)

Column: TSKgel G2500PW _XL (Tosoh Co., Ltd. product), TSKgel G4000 (Tosoh Co., Ltd. product), SHODEX SB-806M-HQ (Showa Denko Co., Ltd. product)

·Eluent: 0.2M phosphate buffer/acetonitrile solution (90/10, PH8.0)

·Column temperature: 40℃

Calibration curve: standard polyethylene oxide-polyethylene glycol

· Measurement method: Dissolve the water-soluble polymer in the eluent so that the concentration is 0.10% by mass, and measure after filter filtration.

Manufacturing (power storage device separator slurry and separator) and evaluation (power storage device)

Example (1)-2-1

(1) Manufacturing (power storage device separator slurry)

The aqueous solution of the electrical storage device separator binder obtained in Example (1)-1-1 was stirred and mixed with 5 parts by mass in terms of solid content and 113 parts by mass of water, and 100 parts by mass of boehmite (average particle diameter 0.8 ㎛) was added as non-conductive particles. , the mixture was dispersed and stirred using a homogenizer (IKA product, T25 digital ULTRA-TURRAX) at 15000 rpm for 60 minutes. Additionally, ion-exchanged water was added to adjust the viscosity to prepare an electrical storage device separator slurry.

(2) Manufacturing (separator): Lamination of a layer (coating layer) of slurry for a separator

A single-layer polyethylene separator substrate (PE substrate) with a width of 250 mm, a length of 200 mm, and a thickness of 6 μm manufactured by a wet method was prepared. The electrical storage device separator slurry was applied onto one side of the separator using a gravure coater so that the thickness after drying was 3.0 μm, and dried to obtain an electrical storage device separator.

Except where otherwise noted, Example (1)-2, Example (2)-2, Comparative Example (1)-2 and Comparative Example (2)- other than Example (1)-2-1. In 2, a power storage device separator was obtained in the same manner as in Example (1)-2-1, except for the changes shown in the table below.

Example (1)-2-9

In Example (1)-2-2, the power storage device separator slurry was coated on a polyethylene terephthalate nonwoven fabric substrate (PET substrate) with a width of 200 mm, a length of 200 mm, a thickness of 9 μm, and a basis weight of 11 g/m2. Except this, the same operation as Example (1)-2-2 was performed to obtain a power storage device separator.

Example (1)-2-10

In Example (1)-2-4, the power storage device separator slurry was prepared as a three-layer (polypropylene/polyethylene/polypropylene) separator substrate (PP) with a width of 250 mm, a length of 200 mm, and a thickness of 20 μm, manufactured by a dry method. A power storage device separator was obtained in the same manner as in Example (1)-2-4, except that it was coated on /PE/PP base material.

Example (2)-2-9

In Example (2)-2-2, the electrical storage device separator slurry was coated on a polyethylene terephthalate nonwoven fabric substrate (PET substrate) with a width of 200 mm, a length of 200 mm, a thickness of 9 μm, and a basis weight of 11 g/m2. (2) The same operation as in-2-2 was performed to obtain a power storage device separator.

Example (2)-2-10

In Example (2)-2-2, the power storage device separator slurry was prepared as a three-layer (polypropylene/polyethylene/polypropylene) separator substrate (PP) with a width of 250 mm, a length of 200 mm, and a thickness of 20 μm, manufactured by a dry method. A power storage device separator was obtained in the same manner as in Example (2)-2-2, except that it was coated on /PE/PP base material.

<Heat shrinkage resistance>

The separator obtained in Example (2)-2 and Comparative Example (2)-2 was cut into a square of 12 cm in width x 12 cm in length, and a square with a side of 10 cm was drawn inside the square to serve as a test piece. The test piece was subjected to heat treatment by placing it in a constant temperature bath at 150°C and leaving it there for 1 hour. After heat treatment, the area of the square drawn inside was measured, the change in area before and after heat treatment was calculated as heat contraction rate, and heat resistance was evaluated according to the following criteria. The smaller the heat shrinkage rate, the better the heat shrinkage resistance of the separator.

○: Area shrinkage rate is less than 1%

△: Area shrinkage rate is 1% or more and less than 3%

×: Area shrinkage rate of 3% or more

<Non-conductive particle adhesion>

Cut the obtained separator into 10cm x 10cm, accurately weigh the mass ( The amount of copper was raised, and they were rubbed for 10 minutes at a rotation speed of 50 rpm. After that, measure the mass (X1) accurately again, and use the formula below:

Amount of powder fall = {(X0-X1)/X0}×100

By calculating the amount of powder falling off (% by mass) according to the following, the non-conductive particle binding property of the separator was evaluated according to the following standards.

A: The amount of powder falling is less than 2% by mass.

B: The amount of powder falling is 2% by mass or more and less than 5% by mass.

C: The amount of powder falling is 5 mass% or more

The smaller the amount of powder falling, the higher the non-conductive particle binding properties are.

<Separator adhesion (peel strength)>

A test piece of 2 cm in width x 10 cm in length was cut from the obtained separator and fixed with the coated side facing up. Next, an adhesive tape (“Sellotape (registered trademark)”, manufactured by Nichiban Co., Ltd.) (specified in JIS Z1522) with a width of 15 mm was pressed onto the surface of the ceramic layer of the test piece. After attaching the adhesive tape under conditions of 25°C, using a tensile tester (“TENSILON RTM-100” manufactured by A&D Co., Ltd.), the adhesive tape is stretched 180 degrees from one end of the test piece at a speed of 30 mm/min. The stress when pulled in the ° direction was measured. The measurement was performed 5 times, converted to a value per 15 mm width, and the average value was calculated as peel strength. The greater the peel strength, the higher the adhesion strength between the substrate and the ceramic layer or the bonding property between the ceramic layers, indicating that it is difficult for the ceramic layer or ceramic layers to separate from the separator substrate.

(3) Manufacturing (electrical storage devices)

In measuring rate resistance and output characteristics, a power storage device was manufactured as follows.

(3-1) Manufacturing (negative electrode)

Using a commercially available rotating mixer (product name “Awatori Rentaro”, manufactured by THINKY CORPORATION), add styrene-butadiene rubber (SBR)/carboxymethylcellulose (CMC) to the container dedicated to the mixer. (Mass ratio 1/1) 2 parts of the aqueous solution in terms of solid content were mixed with 98 parts of natural graphite (manufactured by Ito Graphite Co., Ltd., product name "Z-5F"). Ion-exchanged water was added thereto to a solids concentration of 40%, and the container was set in the mixer. Next, after kneading at 2000 rpm for 10 minutes, defoaming was performed for 1 minute to obtain a slurry for an electrical storage device negative electrode. The slurry for an electrical storage device negative electrode was placed on a current collector made of copper foil, and applied in a film form using a doctor blade. The slurry for electrical storage device negative electrodes applied to the current collector was dried at 80°C for 20 minutes to volatilize the water to remove it, and then closely bonded to the current collector using a roll press machine. At this time, the density of the electrode active material layer was set to 1.0 g/cm2. The bonded product was heated in a vacuum dryer at 120°C for 2 hours, cut into a predetermined shape (rectangular shape of 26 mm x 31 mm), and used as a negative electrode with an electrode active material layer having a thickness of 15 μm.

(3-2) Manufacturing (positive electrode)

88 parts by mass, 6 parts by mass, and 6 parts by mass of LiNi _0.5 Co _0.2 Mn _0.3 O ₂ as a positive electrode active material, acetylene black as a conductive additive, and polyvinylidene fluoride (PVDF) as a binder were mixed, and an appropriate amount of this mixture was mixed. It was dispersed in N-methyl-2-pyrrolidone (NMP) to prepare a slurry for an electrical storage device positive electrode. Next, an aluminum foil was prepared as a current collector for the positive electrode, the slurry for the electrical storage device positive electrode was placed on the aluminum foil, and it was applied to form a film using a doctor blade. The aluminum foil after applying the slurry for the electrical storage device positive electrode was dried at 80°C for 20 minutes to volatilize NMP to remove it, and then was closely bonded with a roll press machine. At this time, the density of the positive electrode active material layer was set to 3.2 g/cm2. The bonded product was heated in a vacuum dryer at 120°C for 6 hours, cut into a predetermined shape (rectangular shape of 25 mm x 30 mm), and a positive electrode with a thickness of the positive electrode active material layer of about 45 μm was obtained.

(3-3) Manufacturing (electrical storage device)

An electrical storage device was manufactured using the above negative electrode and positive electrode. In detail, the separators obtained in Examples and Comparative Examples were sandwiched between the positive electrode and the negative electrode with a rectangular sheet (27 × 32 mm, thickness 25 μm) to form an electrode plate group. This group of electrode plates was wrapped with a set of two laminate films, the three sides were sealed, and then the electrolyte solution was injected into the bag-shaped laminate film. As the electrolyte solution, a solution in which LiPF ₆ was dissolved at a concentration of 1 mol/L in a solvent of ethylene carbonate/ethylmethyl carbonate = 1/1 (mass ratio) was used. After that, the remaining side was sealed to obtain an electrical storage device in which four sides were airtightly sealed and the electrode plate group and electrolyte solution were sealed. Additionally, the positive electrode and the negative electrode are provided with a tab that can be electrically connected to the outside, and a portion of this tab extends to the outside of the power storage device. As a result of energizing the electrical storage device manufactured through the above process, no operational problems occurred.

<Rate resistance, output characteristics>

Using the electrical storage device manufactured above, charging was performed at 0.1 C at 25°C to a voltage of 2.5 to 4.2 V. When the voltage reached 4.2 V, charging was continued at a constant voltage (4.2 V), and the current value was 0.01. The point at which C was reached was considered charging completion (cutoff). Next, charging and discharging at 0.1C to 2.5V was repeated 5 times, and after the 6th cycle, only the discharge was changed to 1C and charging and discharging were repeated for 50 cycles. The ratio of the 1C discharge capacity at the 6th cycle to the charge capacity at the 6th cycle, calculated as a percentage, was taken as the initial rate maintenance rate. The larger this value, the better the rate tolerance. Additionally, the ratio of the 1C discharge capacity at the 50th cycle to the 1C discharge capacity at the 5th cycle, calculated as a percentage, was taken as the capacity maintenance rate. The larger this value, the better the output characteristics.

[Table (1)-2]

[Table (2)-3]

Claims (7)

As a power storage device separator binder aqueous solution,
The electrical storage device separator binder aqueous solution contains a water-soluble polymer (1) or a water-soluble polymer (2) and hydrazide,
The water-soluble polymer (1) contains 20 mol% to 80 mol% of N,N-dialkyl (meth)acrylamide units and 10 mol% to 80 mol% of (meth)acrylamide units,
The water-soluble polymer (2) contains 0.2 mol% to 10 mol% of keto group-containing ethylenically unsaturated monomer units and 65 mol% to 99.7 mol% of (meth)acrylamide group-containing compound units,
The hydrazide has two or more hydrazide groups.
Power storage device separator binder aqueous solution.
According to paragraph 1,
The water-soluble polymer (1) is an electrical storage device separator binder aqueous solution containing less than 40 mol% of unsaturated carboxylic acid and/or its salt unit.
According to paragraph 1,
The water-soluble polymer (2) is an electrical storage device separator binder aqueous solution containing less than 30 mol% of unsaturated carboxylic acid and/or its salt unit.
As a power storage device separator slurry,
The electrical storage device separator slurry contains a water-soluble polymer (1), water and non-conductive particles, or contains a water-soluble polymer (2), hydrazide, water and non-conductive particles,
The water-soluble polymer (1) contains 20 mol% to 80 mol% of N,N-dialkyl (meth)acrylamide units and 10 mol% to 80 mol% of (meth)acrylamide units,
The water-soluble polymer (2) contains 0.2 mol% to 10 mol% of keto group-containing ethylenically unsaturated monomer units and 65 mol% to 99.7 mol% of (meth)acrylamide group-containing compound units,
The hydrazide has two or more hydrazide groups.
Power storage device separator slurry.
A power storage device separator comprising the dried product of the power storage device separator slurry of claim 4 on a substrate.
An electrical storage device separator/electrode laminate comprising the dried product of the electrical storage device separator slurry of claim 4 on the active material side of the electrode.
An electrical storage device comprising the electrical storage device separator of claim 5 and/or the electrical storage device separator/electrode laminate of claim 6.